PERFORMANCE IMPRO VEMENT OF OFDM SYSTEM USING P APR REDUCTION

Orthogonal frequency division multiplexing (OFDM) signals have a generic problem of high peak to average power ratio (PAPR) which is defined as the ratio of the peak power to the average power of the OFDM signal. The drawback of the high PAPR is that the dynamic range of the power amplifier and digital-to-analog converter during the transmission and reception of the signal is higher. As a result, the total cost of the transceiver increases, with reduced efficiency. In this paper, we proposed a method to improve the performance of OFDM System by reduction of Peak-to-Average Power Ratio (PAPR). In this paper, we have combine phasing scheme with companding technique to reduce the PAPR within OFDM systems. Companding OFDM symbols prior to transmission using the μ-Law can significantly improve PAPR reduction. Several authors have proposed schemes for reducing peak amplitude, such as clipping, partial transmit sequence, and selective mapping [1], subcarrier power adjustment [3], linear combination [6]. Here we discussed combining both companding with phasing schemes to improve PAPR reduction. Complementary Cumulative Distributed Function of PAPR reduction techniques is also presented